The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.
Mobile electronic communication devices have evolved beyond simple telephones and are now highly complex multifunctional devices with capabilities rivaling, and in some cases surpassing, those of desktop or laptop computers. In addition to voice communications, many mobile communication devices are capable of capturing images, text messaging, e-mail communications, internet access, social networking, and running full-featured application software. A full range of mobile applications are available from online application stores that can be downloaded onto mobile communication devices. These applications can be games and/or services that provide additional capabilities, such as online banking, stock trading, payments, and other financial activities. Furthermore, mobile communication devices can store confidential or private information such as access codes, passwords, account numbers, e-mail addresses, personal communications, phone numbers, and financial information.
When sensitive and/or private information is transmitted between devices over a public network, such as the Internet, the information is typically encrypted to prevent others from stealing the information. Oftentimes, encryption keys are used to encrypt and/or decrypt the information. In some cases, the communicating devices can share a common encryption key, which is used to encrypt and decrypt the information transmitted between the devices. In other circumstances, a key can be used to protect a device from receiving information from malicious sources. Here, when a device receives information from another device or user, an identification key stored on the receiving device can be used to authenticate the other device or user to ensure that the received information is from an authorized and safe source. For example, the received information can include a key, which is compared to the stored key to determine that the source is safe when the keys match.
In either or both of these cases, the encryption or identification key must be known to the communicating devices and therefore, the key must be initially transmitted from one device to another device. Because a secure communication channel is usually not established between electronic communication devices, a risk of the key being stolen exists when the key is transmitted from one device to another device.
To remedy this problem, some devices are capable of generating a key based on sensor data collected by a sensor in the device when the device is subjected to a physical or environmental stimulus, e.g., a shaking motion. Theoretically when more than one device is subjected to the same environmental stimulus and the sensors collecting the sensor data are of the same type, the keys generated by the devices should be identical. Nonetheless, this is seldom the case because sensors calibrated differently and/or provided by different manufacturers generally do not collect identical sensor data. Accordingly, the keys generated by the devices can be significantly different from each other and therefore unsuitable for secure communications between the devices.